וְדָנִיֵּ֣אל דְּנָ֔ה הַצְלַ֖ח בְּמַלְכ֣וּת דָּרְיָ֑וֶשׁ וּבְמַלְכ֖וּת כּ֥וֹרֶשׁ פרסיא [פָּרְסָאָֽה׃] (פ)
So this Daniel prospered in the reign of Darius, and in the reign of Cyrus the Persian.
Read kabbalistic (mystical) interpretation of Daniel 6:29: and classical mystical sources.